Isoalloxazines



Unite States Patent ISOALLOXAZINES Harold George Petering,

The Upjohn Company, tion of Michigan No Drawing. Application April Serial No. 349,571

27 Claims. (Cl. 26025!1.5

Kalamazoo, Mich., assignor to Kalamazoo, Mich., a corporai, ii

wherein R is an w-formylalkyl group containing from two to six carbon atoms inclusive, R2 and R are members selected from the group consisting of hydrogen, loweralkyl, lower-alkoxy, and amino, and R3 and R4 are members selected from the group consisting of hydrogen, methylene groups linked together to form a carbocyclic ring having from five to six carbon atoms, inclusive, lower-alkyl, lower-alkoxy, halo, and amino, and wherein R2, R3, R4 and R5 when taken together include not more than one amino group, and the hydrates, hydrazones, semicarbazones, thiosemicarbazones, and oximes of said formylalkylisoalloxazines.

It is an object of the present invention to provide novel compounds and derivatives thereof. Another object of this invention is to provide a process for the preparation of these new compounds. Other objects of the invention will be apparent to those skilled in the art to which this invention pertains.

These new and novel compounds are useful as antifungal agents. In addition, the [w-formylalkyll-isoalloxazines and derivatives thereof possess anti-metabolite properties; for example, they are competitively active riboflavin antagonists.

The [w-formylalkyl]-isoalloxazines of the present invention are obtained by reacting a polyhydroxyalkylisoalloxazine of the formula:

wherein R2, R3, R4 and R5 are as defined above, m is an integer from one to five inclusive, and n is an integer from one to four inclusive, with not more than 2.5 times it equivalents of oxidizing agent per mole of polyhydroxyalkylisoalloxazine, to produce the corresponding [wformylalkyl] isoalloxazine. The hydrazones, semicarbazones, thiosemicarbazones and oximes are prepared by reacting the [w-formylalkyll-isoalloxazine thus-ob- 0' tained with a reagent selected from the of hydrazine, semicarbazide, hydroxylamine.

The terms lower-alkyl and lower-alkoxy as used herein include alkyl and alkoxy groups containing from one to five carbon atoms inclusive. The term equivalents refers to the molecular weight of the oxidizing agent divided by the total valence change of the oxidizing agent involved in the reaction. Suitable oxidizing agents include periodic acid, lead tetraacetate, and the like.

According to the preferred procedure for the preparation of an [w-formylalkyl]-isoalloxazine of the invention, the starting polyhydroxyalkylisoalloxazine is suspended in an acid medium such as sulfuric acid, phosphoric acid, acetic acid, or the like, and the suspension reacted, at a temperature maintained between about zero degree centigrade and about fifty degrees centigrade and preferably, not above 25 degrees centigrade, with an oxidizing agent such as periodic acid, lead tetraacetate, or the like. on completion of the reaction, the pH of the reaction mixture is adjusted to the isoelectric point of the [wformylalkyl]-isoalloxazine thus-produced, thereby precipitating the [w-formylalkylJ-isoalloxazine. The solid [w-formylalkyl]-isoalloxazine is removed by filtration or other suitable procedure, washed with solvents such as water, organic water-miscible solvents such as acetone, methanol, ethanol, or the like, and dried to obtain the desired material in substantially pure form.

The [w-formylalkyl]-isoalloxazine prepared by the aforedescribed procedure and subsequently isolated from the reaction mixture can be used in the preparation of its derivatives. It is also feasible to use the reaction mixture, which has been freed or partially freed of the [wformylalkyl]-isoalloxazine, in the preparation of derivatives, as hereinafter described, which are readily removable from the ultimate reaction mass.

The [w-formylalkyl]-isoalloxazine, or the reaction mixture containing this material, can thus be reacted with hydroxylamine, semicarbazide, thiosemicarbazide, hydrazine, or substituted hydrazines, such as, for example, phenylhydrazine, 2,4-dinitrophenylhydrazine, and the like, according to well-established procedures, to produce novel derivatives of the aldehyde compound.

In a more specific embodiment of this invention, a typical and preferred [w-formylalkyl]-isoalloxazine of the invention, such as 6,7-dimethyl-9-formylmethylisoalloxazine, otherwise referred to as 6,7-dimethyl-9-isoalloxazineacetaldehyde, is obtained by reacting a 6,7-dimethyl-9-polyhydroxyalkylisoalloxazine, for example, a glycitylisoalloxazine where n is three, such as riboflavin (otherwise referred to as 6,7-dimethyl-9-(1-D-ribityl)- isoalloxazine), or 6,7-dimethyl-9-(1'-D-arabityl)-isoalloxazine or 6,7-dimethyl-9-(1'-D-lyxityl)-isoalloxazine, or the like, with not more than 7.5 equivalents of an oxidizing agent and preferably between about 6.0 and 7.0 equivalents of oxidizing agent per mole of 6,7-dimethyl- 9-polyhydroxyalkylisoalloxazine.

If the ultimate derivative, i. e., the hydrazone, semicarbazone, thiosemicarbazone or oxime, rather than the free 6,7-dimethyl-9-formylmethylisoalloxazine is to be prepared, an amount equal to two times It equivalents of oxidizing agent per mole of polyhydroxyalkylisoalloxazine is adequate. Lesser amounts of oxidizing agent up to those indicated may also be used. If a 6,7-dimethyl-9- polyhydroxyalkylisoalloxazine such as 6,7-dimethyl-9- (1-D-sorbityl)-isoalloxazine, otherwise referred to as galactoflavin, 6,7 dimethyl-9-(l-D -dulcityl)-isoalloxazine, otherwise referred to as glucoflavin, or the like, is used, wherein n has a value of four, not more than 10.0 equivalents of oxidizing agent are used.

The starting polyhydroxyalkylisoalloxazines are pre: pared by various known methods. For example, in one group consisting thiosemicarbazide and method, a polyhydroxyalkylisoalloxazine is obtained by subjecting an N-mono-substituted aromatic ortho-diam i ne to condensation with an alloxan compound (Kuhn, Ben, 67, 1939, 1934; Karrer, Helv. Chim. Acta, 18, 69, 1935). The condensation of the N-nionosubstituted aromatic ortho-diamine with allozian or N-monosubstituted prod; ucts thereof to produce the isoalloxazine i s preterably performed in acid solution, for instance, in the presence of mineral acids such as hydrochloric, hydrobromic, sul: furic, nitric and phosphoric acid; but the condensation may also be carried out in a strong acetic acid solution, preferably by mining the N-polyhydroxyalkyl aromatic o'r'tlio-diamine with a suspension, of alloxan monohydrate and boric acid in glacial acetic acid, theisoalloxazine thus.- formed usually precipitating from. the reaction mixture i s b n a pur for 7' Instead of using an N-monosubstituted. aromatic. orthodiarnine in; the aboye-described condensation process, an N-monosubstituted aromatic orthonitroamine may be used as the starting material. The reductionv of the orthonitroamine to the corresponding. diamine and the; con d'ensation of: the diamine. thus produced with alloxan may be carried out in a, single step. the N-monosubstituted aromatic ortho-nitroamine is. reacted with the, alloxan compoundin the. presence of a reducing. agent. A leuco compound of theisoalloxazine compound is formed which is subsequently dehydrogenated. by treatment with a dehydrogenatingfagent. Reducing. agents which can be used include, tin, stannous chloride, iron, trivalent titanium, and the. like. Suitable. dehydrogenating agents such as oxygen, potassium pernnmganate,- halogens, 'quinoid dyestufis, and the like, may be used;

Isoalloxazines are. also prepared by reaction of orthoaminoarylazo compounds or ring-substituted (i. e., alkyl, alkoxy, halo, amino groups, and the like) ortho-aminoarylazo compounds with barbituric acid in an acid mediumiU. S. Patent 2,261,608).

Ortho-aminoarylazo compounds may also be condensed with alloxantin or dialuric acid to produceisoalloxazines in accordance with the procedure disclosed in U. S. Patent 2,374,661.

The starting aminoazo compounds are conveniently prepared by the. coupling of substituted phenylamines containing alkyl, alkoxy, halo groups, andthe like, with a diazotized amine in the. manner described by Kar-rer,. Helv. Chim. Acta, 18, 1130, 1935; 19, 264-,- 1936- In another method used inthe. synthesis of-isoalloxazines, the, needtor the. above-indicated. aminoazo compounds. is' eliminated. since N-substituted aromatic amines such as. ribityl orv arabityl xylidine, and. the. like, onmineral salt thereofsuch. as the. hydrochlorides, and the like, can. be condensed directly with voluric acidto yield isoalloxazines in asinglestep.

In another method, polyhydroxylated alleyl nitriles or their )aryl. derivatives may be reductivelycondensed with an aromatic amineto form the corresponding N poly hydroirylate'd.alkylamine, at the acylated N polyhydro'xyl at'ed'alkylamine, which maybe coupled with a dia-Zonium salt, the resulting compound reduced to form the corresponding'diamine and the diarninethus-obtain e d:con; densed with alloxan to form an isoalloxa zine (U. S.-Patent 2,261,608) i The A various 6,-7,-di'all yl-9 polyhydroxyalkylisoallox: azines which are used inthe preparationlo fthe preferred 6,7-di'alkyl-9[w-formylalkyll-isoalloxazines of theinyention may also be obtained according tothe'method of Karrer et al., Helv. Chim. Acta, 17, 1165, 151611934).

A typical polyhydroxyalkylisoalloxazine, riboflavin, otherwise referred to as 6,7-dirnethyl-9-11'-D;ribityl isoalloxazine, was synthesized by Karrer, Helv. Chim, Acta, 18, 5223 5, 1935, and Kuhn, Ben, 68, 1765 74, 1935; The basis of both the Kuhn and Karrer processes is'the condensation of N-(3,4-dimethyl 6 arninophenyl) D-ribamine with alloxan to yield riboflavin. "Karrer carries out this condensation in acid solution (U: S.

Patents 2,155,555 and 2,237,074), whereas Kuhn materially inc eases he yi d of. that nd nsation. by effecting it in glacial acetic acid solution with the use of boric acid as a catalyst (U. S. Patent 2,238,874 and Ber., 68, 1282, 1935). The N (3,4 dimethyl 6-aminophenyl)-D-ribamine required for this condensation with alloxan is prepared by conventional methods such as: (1) condensation of 4,5-dinitro-o-xylene with D-ribalnine followed by catalytic reduction of the product thus-obtained in aqueous el hql s s lut on (Kuhn and; Wes/cane, 68... mar, 1935,);01: (2) condensation of 3 ,4-dimethyl-.6.-.nitroaniline with D-ribose and reduction of the product thus-obtained (Kuhn i 3.1- 6 6.5 3 .x; 1-3 L9 0r (3) condensation of 3 ,4-dimethyl-6-carbethoxyaminoaniline (Karrer et al., Helv. Chim. Acta, 18, 69, 1935;

Y 18, 426, 1935). or- 3-,4-d-ime-thyl-6 acetylaminoaniline (Karrer et al., Ben, 68, 216, 1935) with D-ribose, reduction and saponification of the resulting compound to obtain the free amine, N'-(-.iA-dirnethylaaaminophenyl)- D-ribamine; or (43. condensationof 3,4L-dimethylaniliirc with D -ribose, catalytic reduction of the resnltingtribol side to N-(B'fhdimethyIPhenyl)dlnbamine, coupling thereof; with an aryl diazonium saltto form the: ltd-(3,4- dimethylz-fiaarylazophenyl' )rD-ribamine and reduction of the compound thus-produced to form Ni-( 3',4' dimethyl fieaminophenyl;).-D:ribamine (Karren et all, Helv. Chim. Acta, 18, 1435', 1935:).

Using the last-described procedure, other isoalloxazines, including those containing substituents in the 5, 6, 7 and 8 positions, may likewise be prepared, Thus, the starting.

polyhydroxyalkylisoalloxazines and; intermediates used in the preparation of the [anformylalkyld -isoalloxazines of the invention may be obtained by any of the procedures described supra or other conventional methods disclosed re sa tfollowing; examplesare illustrative of the process and products. of; this invention and, are-not to be, con: strued as, limiting Example 1:-6,7-dimethyl-9 f0rmylmetliylisoalloxazfne and its hydrate A suspension. of, 5.7 grams (0.015, mole); of; 6,7-di methyl-.95l1f-Dgibityl)Tisoalloxazine; (Karrer et a1, Helv.

C im-I cta 17.. 1. .1. 4) in, 150 mill lit rs. ut

na m i lturi c d. spren red. T e su ncnston. is cooled to a temperature of five degrees centigradeand eslu isntcf. er m (Q Si-m l thyd a edzne od c si (-Hi -2 2Q1 n inetn mi lil ters i.w er, .is. dsd hsrsto nd; he. mixture.- rm wh l oclied. n an.-.'. a brfor. ll btained. A h -P .n 3.. h, c dit t .1 adjusted to a pH of about 1.5 by theadditgipn ci solid a ism; arbon tes. Qne' nrt nehai gl'flfl fit fi. asttta i n t h mist mn tataro. reac e 6,71- itnethy -(-.l.- -ribv sorbed thereon are removed by filtr ar onate dde t o h filtrate unt ,afiepi us pre ipit formed; at; this point, the-pH :of? the; mixture; isaabont 3.8. The precipitate is separatedxby,centrifi g gzanfl Washed successiyely With LOO milIiliters of water, fifty milliliters of water, 100 milliliters of alcohol and fifty milliliters of alcohol, theseparationof the solid being effected by centrifuging aftereach washing. After the last washing, the productis suspended infifty milliliters of alcohol, filtered and dried-gin ayacuum desiccator over phosphorus pentoxide. Theyellow-or-ange 6,7-dimethyl- 1- o my me hy isoa lo az n onohydrate w ghs. 3-4 are. 5-. 1. Pe ce di nd as ameltinanoiht of '5: dssrees entiarade (uncorre ted) i hgd 'cpms P 9. nd-Pre ou ark ning- Q enio alg f" fiq 9141. of. Wate r m hehydiate y ea ing, ;2-. methyl-9 forrnylmethylisoalloxazine,is obtained;

fr alysisr calculated' for cinnnnognzos 6; 55:6; i1 18,5? Fc nr tCsi -0; 4; 8

t ne. o r.- unt l. le r-solution Example 2 .6 ,7-a imethyl-9-formylmethylisoalloxazine thiosemicarbazone To a suspension of three grams (0.01 mole) of 6,7-dimethyl-9-formylmethylisoalloxazine monohydrate (Example 1) in 200 milliliters of water is added glacial acetic acid until solution thereof is obtained. A solution of two grams of thiosemicarbazide in 100 milliliters of water is added and the mixture shaken vigorously for several minutes. After chilling the mixture to about four degrees Centigrade in a refrigerator, the solid material thusformed is separated by centrifuging and washed successively with 100 milliliters of alcohol and 100 milliliters of water, the solid being centrifugally separated after each washing. After another Washing with 100 milliliters of alcohol, the product is separated by filtration, washed with a small amount of ether and dried in a vacuum desiccator. There is obtained 2.65 grams (74 percent yield) of an orange colored crystalline material, 6,7 dimethyl 9-formylmethylisoalloxazine thiosemicarbazone, melting at 232 to 233 degrees centigrade (uncorrected) with decomposition and previous darkening.

Analysis.Calc. for CrsHieOzNvS: C, 50.4; H, 4.2; N, 27.5; S, 8.96. Found: C, 50.6; H, 4.5; N, 26.4; S, 9.0.

The hydrazones and the semicarbazones of 6,7-dimethyl-9-formylmethylisoalloxazine are prepared in the same manner using stoichiometric amounts of a hydrazine, illus tratively hydrazine, phenylhydrazine, or 2,4-dinitrophenylhydrazine, or semicarbazide in place of the thiosemicarbazide of the above example.

Example 3.6,7-dimethyl-9-f0rmylmethylisoalloxazine thiosemicarbazone Eight grams of lead tetraacetate (0.0180 mole) dissolved in fifty milliliters of warm glacial acetic acid, is added, with stirring, to a solution of two grams (0.0055 mole) of 6,7-dimethyl-9-(1'-D-ribityl)-isoalloxazine (Example 1) in fifty milliliters of 0.1 normal sodium hydroxide. After standing at room temperature, a deep green fluorescence appears in the mixture at which time ten drops of concentrated sulfuric acid are added and the resulting lead sulfate precipitate removed by centrifuging. The 6,7-dimethyl-9-formylmethylisoalloxazine is precipitated from the solution by reducing the acidity thereof to a pH of about 3.2 and then removed by filtration.

The 6,7 dimethyl 9-formylmethylisoalloxazine thusobtained is reacted with one gram of thiosemicarbazide until a heavy red precipitate is formed. The solid material is removed and successively washed with water, alcohol and ether. A yield of 1.35 grams of 6,7-dimethyl-9- formylmethylisoalloxazine thiosemicarbazone is obtained.

Example 4.-6,7-dimethyl-9 f0rmylmethylisoalloxazine oxime To a suspension of 250 milligrams of 6,7-dimethy1-9- formylmethylisoalloxazine monohydrate (Example 1) in 200 milliliters of water is added glacial acetic acid until solution thereof is obtained. (This occurs at a pH of about 2.3.) A solution of 200 milligrams of hydroxylamine hydrochloride in ten milliliters of water, adjusted to a pH of about 6.7 by the addition of solid sodium carbonate, is mixed with the aqueous solution of 6,7- dimethyl-9-formylmethylisoalloxazine and the resulting mixture shaken vigorously and allowed to stand overnight at room temperature while protected from light. The yellow precipitate thus-formed is separated by centrifuging, washed three times with twenty milliliter portions of alcohol, the solid being centrifugally separated after each washing, and finally dried in a vacuum desiccator. The 6,7 dimethyl 9-formylmethylisoalloxazine oxime thus-obtained melts at about 260 degrees centigrade with decomposition and previous darkening.

Analysis.Calculated for C14H1303N5: C, 5.62; H, 4.35; N, 23.4. Found: C, 56.0; H, 4.35; N, 22.9.

Example 5.5,6-dimethyl-9-formylmethylisoalloxazin Example 6.-5,6-dimethyl-9-f0rmylmethylisoalloxazine thiosemicarbazone Following the procedure described in Example 2 except for the substitution of 6,7-dimethyl-9-fo rmyhnethylisoalloxazine by 5,6-dimethyl-9-formylmethylisoalloxazine (Example 5). 5,6-dimethyl-9-formylmethylisoalloxazine thiosernicarbazone is obtained.

Example 7.6-ethyZ-7-methyl-9-f0rmylmethylisoalloxazine Following the procedure described in Example 1 except for the substitution of 6,7-dimethyl-9-(1'-D-ribityl)-isoalloxazine by 5.9 grams of 6-ethyl-7-methyl-9-(1-D- ribityl)-isoalloxazine (Karrer and Quibell, Helv. Chim. Acta, 19, 1034, 1936), 6-ethyl-7-methyl-9-formylmethylisoalloxazine is obtained.

Example 8.6-ethyl-7-methyl-9-f0rmylmethylisoalloxazine oxime Following the procedure described in Example 4 except for the substitution of 6,7-dimethyl-9-fommylmethylisoalloxazine by 6-ethyl-7methyl-9-formylmethylisoalloxazine (Example 7), 6 ethyl-7-methyl-9-formylmethyli.soalloxazine oxime is obtained.

Example 9.7-mellzyl-9-f0rmylmethylisoalloxazine Following the procedure described in Example 1 except for the substitution of 6,7-dimethyl-9-(1-D-ribityl)-iso alloxazine by 5.4 grams of 7-rnethyl-9-(1'-D-ribityl)- isoalloxazine (Karrer and Quibell, Helv. Chim. Acta, 19,

1034, 1936), 7-methyl-9-formylmethylisoalloxazine is obtained.

Example 10.6,7-dimethyl-9-lw-formylethyl]-is0all0x-' azine Example ]1.6,7-dimezhyl-9- [w-f0rmylethyl] -isoall0xazine thiosemicarbazone Following the procedure described in Example 2 except for the substitution of 6,7-dimethyl-9-formylmethylisoalloxazine by 6,7-dimethyl-9-[w-formylethyl]-isoa.lloxazine (Example 10), 6,7-dimethyl-9-[w-formylethyl]-isoall0xazine thiosemicarbazone is obtained.

Example 12.6,7-dimethoxy-9-formylmethylisoalloxazine Following the procedure described in Example 1 ex-' cept for the substitution of 6,7-dimethyl-9-(1-D-ribityl')- isoalloxazine by 6.1 grams of 6,7-dimethoxy-9-(1-L- arabityl)-isoalloxazine, 6,7 dimethoxy-9-for1nylmethylisoalloxazine is obtained.

Example 13.6-methyl-7-amin0-9-f0rmylmethylisoalloxazine Following the procedure described in Example 1 except for the substitution of 6,7-dimethyl-9-(1'-D-ribityl)-isoal loxazine by 5.7 grams of 6-methyl-7-amino-9-(1'-D-arabityl)-isoalloxazine (Nishida, Rpts. Sci. Res. Inst., Japan, 25, 323, 1949), 6-methyl-7-amino-9-formyhnethylisoalloxazine is obtained.

Example 14.6,7-diethyl-9-formylmethylisoalloxazine Following the procedure described in Example 1 except for the substitution of 6,7-dimethyl-9-(1-D-ribityl) -isoalloxazine by 6.1 grams oi 6,7-diethyl-9-(l' D-ribityl)- isoalloxazine (Lambooy, J. Am. Chem. Soc, 72, 5225, 1950) and the replacement of periodic acid by 22.2 grams of lead tetraacetate, 6,7-diethyl 9-formylmethylisoalloxazine is obtained.

Example 15.6,7-diethyZ 9-f0rmylmethylisoalloxazine thiosemicarbazone Following the procedure described in Example 2 except for the substitution of 6,7-dimethyl-9 formylmethylisoall-oxazine by 6,7-diethy1 9 formylmethylisoalloxazine (Example 14 6,7-diethyl-9-formylmethylisoalloxazine thiosemicarbazone is obtained.

Example 16.6-methyl-7-chl0ro-9-f0rmylmethylisoalloxazine Following the procedure described in Example 1 except for the substitution of 6,7-dimethyl9-(l'-D-ribityl)- isoalloxazine by 6.4 grams of 6-methyl-7-chl0ro9-(l-D- sorbityl)-isoallxazine (Schunk et al., I. Am. Chem. 802., 74, 4251, 1952) and the use of 15.1 grams of periodic acid, 6-methyl-7-chloro 9 formylmethylisoalloxazine is obtained.

Example 17.6,7-dimethyl-9-[w-formylpropyl]-isaalloxazine Following the procedure described in Example 1 exceptfor the substitution of 6,7-dimethyl-9-(1'-D-ribityl)- isoalloxazine by 5.2 grams of 6,7-dimethyl-9-(4,5'-dihydroxyamyl)-isoalloxazine, 6,7-dimethyl-9-[w formylpropyl] -isoalloxazine is obtained.

Example 18.-6 methoxy-7-amino-9-formylmethylisoalloxazine Following the procedure described in Example 1 except for the substitution of 6,7-dimetl1yl-9-(l-D-ribityl)-iso- 'alloxazine by 5.9 grams of 6-methoxy-7-amino-9-(1-D- ribityD-isoalloxazine, 6-methoxy-7-amino-9-formylmethylisoalloxazine is obtained.

Example 19.-6,7-tetramerhyZene-Q-formylmethylisoalloxazine Following the procedure described in Example 1 except for the substitution of 6,7-dimethyl-9-(1'-D-ribityl)- isoalloxazine by 6.0 grams of 6,7-tetramethylene-9-(1- D-arabityl)-isoalloxazine (Kuhn, Ben, 70, 1307, 1937), 6,7-tetramethylene 9 formylmethylisoalloxazine is obtained.

Example 20.-6-methyl-9-formylinethylisoalloxazine Following the procedure described in Example 1 except for the substitution of 6,7-dimethyl-9-(1'-D-ribityl)- isoalloxazine by 5.4 grams of 6-methyl-9-(1-Dribityl)- isoalloxazine (Karrer et al., Helv. Chim. Acta, 18, 1143, 1935), 6-methyl-9-formylmethylisoalloxazine is obtained.

Example 21 .-6,7 dichl0r0-9-f0rmylmethylisoalloxazine Following the procedure described in Example 1 except for the substitution of 6,7-dimethyl-9-('1'- -ribityl)- isoalloxazine by 6.3 grams of 6,7-dichloro-9-(1'-D-ribityl;) -isoalloxazine. (Kuhn et al., Ber-., 76, 1044, 1943), 6,7-dichl0ro-9:formylmethylisoalloxazine is obtained.

Example 22;--6,8-dimethyI-9-f0rmylmethylisoalloxazine Following the procedure described in Example 1 exception the substitution of 6-,7-dimethyl-9-(1'-D-ribityl) isoalloxazine by 5.7 grams of 6,8-dimethyl-9-(1-D-ribityl),-is,oalloxa z ine (Kuhn et al., Ber., 70, 1293, 1937),

6',fledimethylfl-f0rmylmthylisoalloxazine is obtained. a Example.- 23;e-6echloro-9-formylmethylisoallqxazine F '11 win the procedure described in Example 1 exsu st: ution of 6,7=dimethyl-9-( 1"-D -ribity1) isoalloxazine by 5.8 grams of 6-chloro-9-(1'-D-arabityl) lsoalloxazine (Schunlc et al., J. Am. Chem. Soc., 74, 4251', 1952), 6-chloro-9-formylmethylisoalloxazine is obtained.

Example 24.--5,6,7,8 tetram'ethyl-9-f0rmylmethylis0alloxazine Following the procedure described in Example 1 ex- Cept for the substitution of 6,7-dimethyl9-(1-D-ribityl)- isoalloxazine by 6.1 grams of 5,6,7,8-tetramethy1-9-(1'-L- arabityl).-isoalloxazine and the use of 11.4 grams of periodic acid, 5,6,7,8-tetrarnethyl9-formylmethylisoallox azine is obtained.

Similarly, other. [weformylalkyl] -isoalloxazines, areprepared such as, for example, 9-formylmethylisoalloxazine, .9-[o-formylethyl1-isoalloxazine, 9-[w.-formy1propy1]-iso.- alloxazine, 6-methyl-7-ethyl 9-formylmethylisoalloxazine,, 6rnethyl,- 7 propyl-9-formylmeihylisoalloxazine, 6,7.di. methy1-9-[w-formylbutyl],-isoal1oxazine, 6,7 dimethyl-Q [w formylamyl] isoalloxaziue... 6,7-diethyl-9-[w -formyk ethyl] -is0alloxazine, 6,7-diethoxy-9-formylmethylisoalloxazine, 6,7-dipropyl-9-forrnylrnethylisoalloxazine, 6,7-dipropoxy-9-formylmethylisoalloxazine, 6 amino-7-methoxy-9-formylmethylisoalloxazine, 6 meth0xy-7-amino-9- [w formylethyl]-isoa1loxazine, 6,7 dimethoxy-9-[w-formylethylJ-isoalloxazine, 6-propyl-7-methyl-9-formylrnethylisoalloxazine, 6-methyl-7-propyl-9-[w-formylethyll-isoalloxazine, 6,7-diamyl 9 formylmethylisoalloxazine, 6- methoxy-7-chloro-9-forrnylmethylisoalloxazine, 6-methyl- 8-isopropyl-9-formyln1ethylisoalloxazine, 6,7 dibutyl-9- formylmethylisoalloxazine, 6,7-trimethylene 9 formylmethylisoalloxazine, 7,8 dimethyl 9-formylmethylisoalloxazine, 5,6,7 -trimethyl 9 formylmethylisoalloxazine, 5,6,7-trimethyl-9-[w-formylethyl]-isoalloxazine, 5,6,7-trimethyl-S-methoxy 9 fcrmylmethylisoalloxazine, 6,8-dimethoxy-7;-methyl-9-formylmethylisoalloxazine, fi-chloroe 7,8-dimethyl-S?-formylmethylisoalloxazine,v 5-methyl-8-iso propyl-9-formylmethylisoalloxazine, 5,7-dimethyl-6-methoxy-9-formylmethylisoalloxazine, 5,8-dimethyl-7-ethoxy- 9-formylmethylisoalloxazine, 5,6,8 trimethyl-7-aminow9- formylmethylisoalloxazine, 5,6,7,8-tetramethyl-9-[w formylethyll-isoalloxazine, and the like, and the hydrates, hydrazones, semicarbazones, thiosemicarbazones and. oximes. of, these [w-formylalkyl] -isoalloxazines.

' It is to be understood that the invention is not to be limited tothe exact details of operation or exact, compounds shown, and described, as obvious modifications and equivalents will be apparent to one. skilled in the art andv the invention is therefore to be limited only by the scope of, the appended claims.

Iv claim:

1., [w-Formylalkyll-isoalloxazines represented, by the formula:

wherein R is. an w-formylalkyl group containing frorntwo to six carbon: atoms inclusive, R2 and R5 are members selected from, the group consisting ofhydrogen and, loweralkyl, R3 and R are members selected from the group consisting of hydrogen, a tetrarnethylene group linked together to form a carbocyclic ring having six carbon atoms, lower-alkyl, lower-alkoxy, chloro, and amino and wherein R2, R3, R4 and Re When taken, together include not more than one amino group and the hydrates, hydrazones, semicarbazones, thiosemicarbazones, and oximes of said lw-formylalkyllisoalloxazines.

2. Ortho di lower alkyl 9 [w formylalkyl] isoalloxazine.

3. 5,6 di lower alkyl 9 alloxazine.

[w formylalkyl] iso 4. 5,6-dimethyl-9-[w-formylakyH-isoalloxazine.

5. 5,6-dimethyl-9-formylmethylisoalloxazine.

6. 6,7-di-lower-alkyl-9- w-formylalkyl] -isoalloxazine.

7. 6 lower alkyl 7 methyl 9 [w formylalkyl]- isoalloxazine.

8. 6 lower alkyl 7 ethyl 9 [w formylalkyl] isoalloxazine.

9. 6 ethyl 7 lower alkyl 9 [w formylalkyl] isoalloxazine.

10. 6,7 dimethyl 9 [w-formylalkyl]-isoalloxazine.

11. 6,7 di-lower alkyl 9 formylmethylisoalloxa- Zinc.

12. 6,7 di lower alkyl 9 [w formylethyl] isoalloxazine.

. 7 lower alkyl 9 [w-formylalkyH-isoalloxazine. 7 lower alkyl 9 formylmethylisoalloxazine. 7-methyl-9-formylmethylisoalloxazine. 6,7-dimethyl-9-formylmethylisoalloxazine.

6 ethyl 7 methyl 9 formylmethylisoalloxa- 6,7-dimethyl-9-[w-formylethyl]-isoalloxazine. 19. The process for the preparation of [w-formylalkyllisoalloxazines of the formula:

it. 2) wherein R2, R3, R4 and R are as defined above, In is an integer from one to five inclusive, and n is an integer from one to four inclusive, by reaction with up to 2.5 times n equivalents of an oxidizing agent selected from the group consisting of periodic acid and lead tetraacetate per mole of said polyhydroxyalkylisoalloxazine to produce the corresponding [w-formylalkyl]-isoalloxazine.

20. A process for the preparation of [w-formylalkylJ- isoalloxazines of the formula:

wherein R is an w-formylalkyl group containing from two to six carbon atoms inclusive, R2 and R5 are members selected from the group consisting of hydrogen and, loweralkyl, R3 and R4 are members selected from the group consisting of hydrogen, a tetramethylene group linked together to form a carbocyclic ring having six carbon atoms, lower-alkyl, lower-alkoxy, chloro, and amino, and Wherein R2, R3, R4 and R5 when taken together include not more than one amino group and formylalkyl group derivatives thereof, which comprises the steps of reacting a polyhydroxyalkylisoalloxazine of the formula:

wherein R2, R3, R4 and R5 are as defined above, in is an integer from one to five inclusive, and n is an integer from one to four inclusive, by reaction with up to 2.5 times It equivalents of an oxidizing agent selected from the group consisting of periodic acid and lead tetraacetate per mole of said polyhydroxyalkylisoalloxazine to produce the corresponding [w-formylalkyH-isoalloxazine, and reacting the [w-formylalkyl]-isoalloxazine thus-obtained with a carbonyl group reagent selected from the class consisting of hydrazines, semicarbazide, thiosemicarbazide and hydroxylamine.

21. A process for the preparation of a 6,7-di-loweralkyl-9-formylmethylisoalloxazine which comprises reacting a 6,7-di-lower-alkyl-9-(glycityl)-isoalloxazine with up to 7.5 equivalents of periodic acid per mole of said 6,7- di-lower-alkyl-9-(glycityl)-isoalloxazine to produce a 6,7- di-lower-alkyl-9-formylmethylisoalloxazine.

22. A process for the preparation of 6,7-dimethyl-9- formylmethylisoalloxazine which comprises reacting one mole of a 6,7-dimethyl-9-(gIycityD-isoalloxazine with up to 7.5 equivalents of periodic acid per mole of said 6,7- dimethyl9-(glycityl)-isoalloxazine to produce 6,7-dimethyl-9-formylmethylisoalloxazine.

23. A process for the preparation of 6,7-dimethyl-9- formylmethyl-isoalloxazine which comprises reacting one mole of a 6,7-dimethy1-9-(glycityl)-isoalloxazine with up to 7.5 equivalents of lead tetraacetate per mole of said 6,7- dimethyl-9-(glycityl)-isoa1loxazine in an acid medium to produce 6,7-dimethyl-9-formylmethylisoalloxazine.

24. A process of preparing 6,7-dimethyl-9-formylmethylisoalloxazine comprising reacting 6,7-dimethyl-9-(1-D- ribity1)-isoalloxazine with up to 7.5 equivalents of periodic acid per mole of 6-7-dimethyl-9-(1-D-ribity1)-isoalloxazine to produce 6,7-dimethyl-9-formylmethylisoalloxazlne.

25. A process of preparing 6,7-dimethyl-9-formylmethylisoalloxazine comprising the step of mixing one mole of 6,7-dimethyl-9-(l'-D-ribityl)-isoalloxazine with between 6.0 and 7.0 equivalents of lead tetraacetate and reacting the resulting mixture in an acid medium to produce 6,7-dimethyl-9-dimethyl-9-formy1methyl-isoalloxazine.

26. A process for the preparation of 6,7-dimethyl-9-[wformyl-ethyH-isoalloxazine which comprises reacting 6,7- dimethy1-9-(1-D-sorbityl)-isoalloxazine with up to 10.0 equivalents of periodic acid per mole of said 6,7-dimethyl- 9-(1'-D-sorbityl)-isoalloxazine to produce 6,7,-dimethyl-9- [w-formylethyH-isoalloxazine.

27. Crystalline 6,7-dimethyl-9-formylmethylisoalloxazine monohydrate having a melting point of 258 to 259 degrees centigrade.

No references cited. 

1. (W-FORMYLALKYL)-ISOALLOXAZINES REPRESENTED BY THE FORMULA:
 20. A PROCESS FOR THE PREPARATION OF (W-FORMYLALKYL)ISOALLOXAZINES OF THE FORMULA: 